Many of us have handed down family snapshots, yearbook pix, wedding pix &c. We might not even know who took the picture, but I always assume it's OK to post pictures taken by relatives who are gone. I guess I figure I inherited the rights to reproduce along with the photos themselves.
I do wonder about pictures found on ancestry.com from public records like, say, a passport application. It's a public record, but the digital copy is beyond a subscription wall. I've extracted pictures - in some cases the only picture I've ever seen of the person. I've put those on my ancestry tree, but not here. It is a public record, and I've also extracted, cropped and often tweaked in PhotoShop (mostly contrast & brightness adjustments) Same deal about pages from books long out of copyright, but digitized by others.